Belt



` A. L.. FREEDLANDER 2,024,443

BELT

original Filed Feb. 12, 1s4 4 sheetsheex 2 Dec. 17, 1935.

u Twvondnf/ ABRAHAM LFREED'LANDER,

a/oucm Dec. 1 7, 1935.

A. L. FREEDLANDER BELT Original Filed Feb. l2, 1934 4 Sheets-Sheet 3 5 mm, e 4 mw l- |||-|I. l .l A M+T.. 4 a E ||||||..|l..||||ll h n n I M l l M u A u u R l l l l U l l I l I l |||1 |LL l l dll. l l l l l l l l .llll 5 .::2 M A@ 4 l- I4. 4 m 4 1S HH. 5)/. 6. 6. 2 F r m Dec. 1`7, 1935.

A. L. FREEDLANDEFQ BELT , 1934 4 Sheets-Sheet 4 Original Filed Feb.'

uZON .conukmou Imm ABRAHAM LFRE'EDLANDER,

Patented vDee. 17, '193s UNITI-:D STATE s PATENT vorricl;

BELT

Abraham L. Freedlandcr, mDayton, Ohio, assigner to The Dayton Rubber Iltianufaeturing: Comrally, Dayton, Ohio, a corporation of Ohio original appiienxinn February 12, 1934, serial No.

. 710,821.- nividea and ibis application septem- ,V ber 4,1934, serial No. 742,572

ircinims. (omi-23s) This invention relates to heus and especially to layers of fabric composing one group are laidwith progressively-increasing tensions until the n middle layer ofthe group is reached, and then with progressively-decreasing tensions until the outer layer on the other side 'of the group is reached.

Another object is to provide such a belt having an. inner wrapper and an outer wrapper over the other in construction.

This'application is a division of my applicanon ser. Ne. '110,821,111edr'eb. 12,1934.

In the drawings: v Figure 1 is adiagrammatic viewofthe apparatus forl winding the layers of rubberized fabric upon. one another in forming the core oiv the belt; Y

' Figure 2 is a section through the winding drum I shown in Figure 1. illustrating the groups of layers of rubberized fabric; f

Figure 3 is a cross section through the belt showing the application of the inner wrapper or cover; .n A y )Figure 4 isl across sectional view of the finished belt, shown in Figure 5, after the outer wrapper or cover has been applied to the construction of Figure 3; Figure l25 vis. 'aside elevation of a section of the anished belt;

Figure 6 is a topplan view of the ni'shed'belt; ""Figure 7 is a diagrammatic side elevation of the pre-forming apparatus; .Y

Figure 8 isan end elevation showninFigure '1;4

of the apparatus Figure 9 is a side" elevation, partly in sertion,

showing the belt being frozen while in a stretched condition:v l

Figure 10 is a perspectlveview of the belt showing the application of the cover stripoverthe teeth;

Figure 11 is a diagrammatic plan view, partly broken away, of an open-ended toothed mould for curing the belt under tension;

Figure 12 -is a side elevation, partly in section,

55 ofthemouldshowninFigureu;

core, the two wrappers diiering from one an- 5 in hanger 22.

bearing block 23 which is forced against it by 55,V

Figure 13 is atop plan view of the belt of my invention with the layers thereof 'successively broken away to expose the underlying layers.v

Figure 14- is a perspective View with the belt split longitudinally along one6 of the layers there- 5 `of and the top part raisedY to expose the fabrictherein. v'

Figure 15 is a Adiagrammatic cross section il -lustrating the principles involved in the con'struction of my belt.

Method and apparatus for' making the belt Referring to the drawings inv detail, Figure 1 shows a. strip of rubberized fabric l which is rolled upon a spool 2. This rubberized fabric is 15 '3 composed of square-woven textile material which e has been impregnated with soft vulcanizable rubber in a rubber mixing mill, generally a pair of rolls moving at different speeds. The `sheet of.

fabric with the rubber mixed with it is then.20

Ipassed through a calender machine which forms the product into a sheet of rubberized fabric. Thistrubberized fabricv is very sticky and will readily adhere to other layers of fabric and maintain the ygeneral formand shape given-it despite 25 the cutting or handling operations to which it is subjected.

The rubberized fabric strip I passes from the spool 2 over the guide rollers 3 endl, across the stretehing table 5, over the guide rollers' 6 and 1, 30 around the tension roller 8 and on to the formv 4ing cylinder 9. The latter is provided` with anV end plate I0 anda gear wheel II on theopposite lside thereof (Figure 2). Both are attached to -der 9 is `provided with spokes I4 leading tov hub portions if! engaging the shaft I2. Accordingly by removing the end plates i0 and/or II, the cylinder 9 may be removed from its appa.- 40

ratus. 4 The driving apparatus for the cylinder 9 (Figure 1) 4consists of an idler gear I-I meshing with the gear whe il on the drum. On its opposite side, the idler ear -I1 meshes with the gear il mounted on the shaft', I9 of a suitable power 45 source, such as an electric motor, generally des-l ignated 20. Wher.- 'the motor 20 revolves .the shaft I9, the drum 9 is accordingly rotated and winds in the fabric strip I on to its periphery.

As hereinafter shown, the different layers or rubberized fabric are sometimes laid while under;l tension. To provide this tension, the roller 8 is mounted on a sh t. 2l which is.half supported ts other half is engagedby a the shaft I2 as lby the set screws I3. The-cylin- 35.

the screw 24 so as to apply any desired amount of frictionto the shaft. By tightening the screw 24, the roller 8 is given an increasing amount of retardation, causing the fabric to be wound upon the drum 9 in a state of increasing tension. It will be understood that the fabric I does not slide on the tension roll 8, because of its extremely sticky condition.

In building up the core, the drum 9 is made of such diameter that its circumference somewhat exceeds the length of the belt to be produced. AIts Width is made of any convenient amount to produce the number of belt cores desired at -one operation.

'Ihe innermost section 25 or first laid layers of rubberized fabric form the part of the belt which is cut away, as at 26 (Figure 5), to provide teeth 21 on the inner surface thereof. The tooth section 25 of rubberized fabric layers is formed by slowly revolving the drum 9 while a plurality of layers of rubberized square-woven fabric is wound upon it, without any tension upon the fabric, other than the slight tension naturally existing in feeding from the spool 2 to the cylinder 9. This fabricis straight-laid. In a 2" belt, for example, the tooth section 25 has about thirteen plies.

The tooth section fabric is then severed and the compression section layers 28 applied. These layers lie immediately above the tooth section 25 in the finished belt and are formed of a plurality of layers of the same rubberized fabric, but laid on the bias, and without tension. The bias-laid fabric enables the compression section of the belt to be compressed somewhat during the use of'the belt without injury thereto. These plies lie just above the teeth in the finished belt and are applied on the bias so as to withstand the movement between the body of the belt and the teeth. In a 2" belt, about four plies of this bias-laidabric are found suitable. The bias-,laid fabric forming the compression section 28 of the belt is then severed and the neutral zone and ten' sion section 29 laid over it.

The se portions 29 and 30 of the belt are. composed of the same square-woven rubberized fabric. 'I'his is straight-laid, but with varying amounts of tension between the different layers. It is found preferable to progressively increase the tension as each succeeding layer at the neutral zone is laid, until the middle layer is reached;v and then to progressively decrease `the tension until the outermost layer is reached. For example, in using seven plies or layers of fabric, it is found suitable to give the first layer a stretch or tension per yard of approximately'f, the second layer 5/3", the third layer l, the fourth or middle layer 11A", the fifth layer l", th sixth layer and the seventh layer 1%". Thus the stretch or tension is varied in the different plies or layers.

according to their positions relative to the middle layer 30 or the neutral axis of the group. This middle layer 30 becomes the neutral axis layer of the finished belt.

With the final layer of the tension section 29 of the belt thus laid, the rubberized fabric is severed and the shell of rubberized material on the drum cut circumferentially into individual belt cores, each having the desired. width and angle of side walls. Two lines are then drawn across the plurality of belts parallel to the axis of the drum, these lines being separated by a known peripheral distance, such as 36", for example. The cores are then removed from the drum by severing them with a knife passed longitudinally along the rim of the drum.

The belt cores are then given a coat of. rubber cement and allowed to dry, during which operation they usually shrink slightly. The cores 5 are then stretched out on ,a table'until the two reference marks regain their original separation,

such as 36", thus bringing the stretch of the belt back to the condition lwhich it had when thebelt core was built. belt material forming the core maintains its general form because of the sticky nature of the rubberized fabric layers, of which it is composed, despite the fact that vulcanization has not yet taken place. 15

The belt core is now wrapped while it is stretched out on the table. The wrapper is applied to the belt in a stretched position so that it will not be strained during the subsequent stretching operations, and also because it promotes longer life in the belts while they are in use.

'I'he wrapper assembly is composed of two parts (Figures 3 and 4), an inner cover 3| and an outer cover 32. Both covers are of bias-laid fabric, square-woven and rubberized. The inner cover extends around three sides only of the belt core, namely, the inner surface and side walls. 'Ihe outside cover, however, fully encloses the belt core and the inner cover, and is lapped over itself for the entire width of the belt across the top thereof. After the covers have been applied, they. are rolled down into place.

The belt thus covered is now run through the pre-forming machine (Figures 7 and 8) in order 35 to form it more nearly to its nal shape. The Y pre-forming machine is in its essence a pair of rollers 33 and 34. The lower roll 34 is provided with a peripheral groove which has the approximate shape of the belt cross section: this 40 roll is power driven. The upper roll 33, however, has a slightly convex periphery and is driven by the friction of the belt passing underneath. The pressure of the upper roll 33 forces the belt downward into the groove and causes it to take on the cross sectional shape thereof..

After the pre-forming operation has been completed the belt is stretched out and clamped in its stretched position in a trough 40. In the belt considered as an example, it has been found that 11/2 of stretch per yard is satisfactory so that the two marks which were originally 36" apart are now 371/2 apart. The stretched belt is now surrounded by solidied carbon dioxide, commonly known as dry ice, and allowed to freeze for approximately twenty minutes. The clamps are now removed but the belt retains its stretched length becauseof its being frozen. The frozen belt is immediately put through the punch press which punches out the cut-away portions 26 to ov form the teeth 21. The punch press die is provided with a plunger-locating' device which causes the teeth to be properly spaced. While the belt ,cemented thereto, in order to'protect the surface thereof.

The belt is now cured in an' open-ended mould 42. This mould is` provided with toothed portions 43 which are spaced apart from one an- 75 During thesesteps, the mass of 10A In the belt considered as an example, l

;: of lav cable and windlass until the teeth on the belt are stretched out sufficiently to iit into the toothed -portions 43 in the mould l2. When the beit isv in the mould, the two ,marks which were originally about 36" 'apartware now 37" apart.

. lo; :,.The mould is approximately thirteen feet long and is: provided with wa r-cooling portions Il ateach end. These wate -cooling portions are used-to prevent an over-curing of the belt, where the latter is of such length that it must be cured more than cnce.v In the belt conside as-an example, this curing then isy about sixty-five minutes at about 286 degrees Fahrenheit.

After curing, the belt' is removed from-the mould. It now shrinks somewhat as it cools, the belt under consideration having -an eventual length of about 361/2" between the marks. 'I'he belt is now trimmed, if necessary. to remove projecting parts orv excessive site and thus reaches its finished state. v Tnenmsned beit. britdv described,v thus consists of a-core having a toothed portion 25 with away portions 2B on the inner surface thereof.

- AThe belt of my invention is thus adapted, because of its construction as above disclosed, to maintain a substantially constant length along its neutral axis, despite conditions of intensive use.

It will be understood that I desire to comprebend within my invention such modifications asmay b'e nec tions anduses Having thus, fully describedl my invention,`what I claim as new and desire to secure by Letters Patent is:

l. A belt comprising a plurality of `layers of rubberized fabric arranged in groups,.one group having straight-laid layers arranged without tension. another group having bias-laid layers arranged without tension, and a third group having 'layersxarranged at varying tensions relative to one-another.

e 2. A belt comprising-a plurality of layers vofl rubberized fabric arranged in groups, one group having straight-laid layers arranged without tension, another group having bias-laid layers arranged without tension, and a .third group having straight-laid laiyers arranged at 'varying tensions relative to one another. 3. A beit comprising a pluralityof layers of rubberized fabric arranged in groups, one group having straight-laid layers arranged without tension. another group having bias-laid layers arranged without tension, and a third group having straight-laid layers arranged at varying tensions relative to one another. said first-mentioned 70 group having toothed portions formed therein.

1 4. In combination in a belt of' a plurality of inner layers 'of rubberized fabric arranged without tension, a plurality o f superimposed layers arranged with progressively increasing tension, -7b and a plurality of superimposed layers of proto adapt it to varying condi- 3f gressively decreasing tension, .said belt being so arranged that the zone of maximum tension sub--- gtantially coincides withthe neutral axis-cf the,` v elti s. In combination 1n vc beit or.`a.'p1u'ra.1ity'or. 5..l

inner layers of rubberized fabric arranged without tension,'a plurality of superimposed layers arranged with progressively increasingtension, and -a plurality of superimposedl layers of' progressively 4decreasing' tension. '.'said ybelt being-10..

so arranged that the. zone of maximum tension substantially coincides with the neutral axis `of v the belt, said first mentioned layer having sections sheared therefrom transversely of the belt to form a plurality of transversely arranged teeth 35.'

on the innersurface of the belt. 6. In combination in a belt, a plurality straight laid layers of rubberized fabric arranged straight laid 'fabric under tension progressively 25 decreasing in tension from the bottom of the lay- `fabric under tension. and increasing progressive- 35 ly in tension from the bottomto the top of the layers, a second group of layers of-rubberized straight iaid'fabric'under tension progressively decreasing in tension from the bottom of. the

layers to the toll, Said region of maximum ten- 4o sion of the last-tw@ groups of layers being substantially in the neutral axis of the belt, said first mentioned group of layers having portions thereof sheared transversely of the belt to form teeth on the inner surfaceof the belt. c

8. In combination in a belt, f a plurality of straight laid layers ofrubberized fabric arranged without tension, a plurality of superimposed layers of bias laid rubberized fabric without tension,

a plurality of straight laid layers of rubberized fabric under tension and increasing progressively in tension from the bottom to the top o f the layers, a second group of layers of rubberized straight laid fabric under tension progressively decreasing in tension from the bottom of the layers to'55 the top, said region-of maximum tension of the last two groups of layers @being substantially in the neutral axisV of the belt, said first mentioned group of layers having portions thereof sheared transversely of the belt to form teeth on the inner surface of the belt, and an inner cover layer mounted on the inner face of said belt over said teeth comprising rubberized fabric.

9. In combination` in a belt of a plurality of y inner layers of rubberized fabric arranged "without tension, a plurality of superimposed layers arranged with progressively increasing tension, kand a plurality of superimposed layers of progressively decreasing tension, said belt being so arranged that the zone of maximum tension suby stantially coincides with the neutral axis of the y belt, and a cover of rubberized fabric for the bot'- tom and side walls of said belt, anda second cover of rubberized fabric. for the bottom, side .walls and top o f said belt.

w. In combination in a belt of a plurality of inner layers oi rubberized fabric arranged Without tension, a plurality oi superimposed layers arranged with progressively increasing tension, and a plurality of superimposed layers of progressively decreasing tension, said belt being so arranged that the zone of maximum tension substantially coincides with the neutral axis of the belt,A said drst mentioned layer having sections VShearer?. therefrom imansversely of the belt to form. a plurality of transversely arranged teeth on the inner surface ci the belt, a ccver of rubberized fabric for the bottom and side wallsroi said belt,y and a secondcover of rubberized fabric for the bottom, side wails and top of said belt.

1l. m combination in a belt, a plurality of straight laid layers of rubberized fabric arranged without tension, a plurality of superimposed layers of bias laid rubberized fabric without tension, a plurality of straight laid layers of rubberized fabric under tension and increasing progressively 5 in tension from the bottom to the top of the layers, a second group of layers of rubberized straight laid fabric under tension progressively decreasing in tension from the bottom of the layers to the top, said region of maximum tension of the las* two groups of layers being substantially in the neutral axis of the belt, a cover cf rubberized fabric for the bottom and side walls of said belt. and a second coverof rubberized fabric for the ABRAHAM L. 

